How to Give a Semaglutide Injection: A Step-by-Step Guide

Your first injection: what the moment actually looks like

Picture this: it's a Tuesday morning, your Wegovy pen has been sitting on the kitchen counter for half an hour, and you're standing in the bathroom wondering if you're about to do it right. That slight apprehension is entirely normal, almost everyone feels it before the first self-injection, regardless of the needle size involved. The Wegovy pen is designed for exactly this moment.

Remove the pen cap. Check the small dose window on the side: you should see the correct dose number, not a blocked or cloudy indicator. The liquid inside may appear clear to slightly yellow, both are normal. Don't shake the pen. Select your site. For most people starting out, the lower abdomen (avoiding the two inches directly around the navel) is the easiest to reach and visualise. Pinch a fold of skin lightly if you prefer, though this isn't required for all pen types, your leaflet will specify.

Press the pen flat and firmly against the skin, then press and hold the injection button until you hear or feel a click, keeping it pressed for a further ten seconds. This ensures the full dose is delivered. Lift the pen away. A small red dot or pinprick of blood is normal; press gently with a clean finger for a few seconds. Do not rub, it can increase local irritation. The semaglutide pre-filled pen is single-use; the needle retracts automatically on most Wegovy devices. Place the used pen in a sharps container immediately, never in the household bin.

The NHS semaglutide medicines page has concise guidance on injection technique that's worth bookmarking alongside your leaflet.

Choosing and rotating your injection site, why it matters more than most people realise

Semaglutide is absorbed through the fat layer just beneath the skin. Injecting into the same small area every week means that tissue gets little chance to recover, which can lead to lumps, thickened skin, or reduced absorption over time, a phenomenon called lipohypertrophy. Rotating properly sidesteps this almost entirely.

The three approved sites are the abdomen, the front of the thigh, and the outer upper arm. Within each site, shift the exact spot a few centimetres each week. A simple system: abdomen for the first four weeks, thigh the next, upper arm the next, then back to the abdomen. Some people prefer to pick one site and rotate systematically within it, either approach works as long as you're not returning to the identical spot repeatedly.

If you'd like more detail on using the thigh specifically, our guide to injecting semaglutide in the thigh covers positioning, skin-fold technique and what to expect. For the abdomen, the stomach injection guide walks through the distance-from-navel rule in more detail. Avoid broken, bruised, or irritated skin wherever you inject. If you notice persistent redness, swelling, or hardened skin at a site, mention it at your next clinical review.

One practical note: the upper arm is harder to reach solo. Some people use a mirror, others ask a household member. There's no clinical reason to avoid it, it's just a matter of logistics.

Storage, timing and the weekly rhythm that keeps treatment on track

Wegovy pens are stored in the fridge between 2°C and 8°C. Take the pen out roughly 30 minutes before you plan to inject, a cold pen can make the injection more uncomfortable and may affect delivery. Do not freeze the pen, and keep it away from direct light. Once removed from the fridge, the pen can be kept at room temperature for a limited period; the exact window is stated in the Patient Information Leaflet, and it can differ between batches and pen types, so the leaflet is always the authority on this point, not a general estimate found online.

Pick a consistent day of the week that fits your routine naturally. Many people anchor it to something fixed: the same morning they do a weekly food shop, or the evening before a regular gym session. Consistency reduces missed doses and makes the titration schedule easier to track. If your dose is being increased, your prescriber will confirm the timing; dose changes happen at roughly four-weekly intervals and are based on your response and tolerability, not a fixed calendar.

It's worth knowing that semaglutide comes in different branded forms. Ozempic is also semaglutide, but it is licensed for type 2 diabetes management rather than weight loss, the injection technique is similar but the clinical context is entirely different. Wegovy is the brand licensed for weight management in the UK. If you have questions about which treatment is right for you, or you're considering starting, our page on weight loss treatment options is a good starting point.

Side effects at the injection site and when to seek help

Local reactions (a small bruise, mild redness, or a brief stinging sensation) are common and usually resolve within a day or two. They tend to be most noticeable in the first few weeks of treatment. Good technique (room-temperature pen, correct site rotation, slow steady pressure) reduces their frequency.

Beyond the injection site, semaglutide's side effects are predominantly gastrointestinal: nausea, loose stools, constipation, burping, and indigestion are the most frequently reported, particularly after starting or following a dose increase. For most people these settle within a couple of weeks. Our page on pins and needles with semaglutide covers one of the less commonly discussed sensations that some people notice during treatment.

A small number of people experience a more unusual sensation: tingling or numbness near the injection site. This is generally benign and linked to a superficial nerve being nudged during the injection. Varying your technique slightly (injecting at a slightly different angle, or switching sites for a few weeks) often resolves it.

Seek urgent medical attention for severe, persistent abdominal pain that radiates to the back, this can be a sign of pancreatitis, and the MHRA has flagged this as a known, though infrequent, serious side effect of GLP-1 medicines. Other signs to act on promptly include severe allergic reactions, significant dehydration from prolonged vomiting or diarrhoea, and any symptoms of low mood or thoughts of self-harm. You can report suspected side effects directly to the MHRA via the Yellow Card scheme.

If you're thinking about starting semaglutide treatment and want to understand whether it's suitable for you, check your eligibility with a free consultation, a GPhC-registered prescriber will review your answers the same day.